Translate a lexer file with a format similar to re2c (http://re2c.org)
into a PHP 5 lexer for use with a parser.

Unlike re2c (as of re2c version 0.11), generated lexers are state-aware
out of the box.

Generated lexers are very efficient, more than twice as efficient as other
alternatives like csLex (written in C#) because they utilize PHP's
built-in Perl-compatible regular expressions to lex for tokens.

Now in version 0.3.0+, with processing instruction %longestmatch, generated
lexers will always pick the longest string to match, rather than the first.
Generated lexers are slightly slower, but match behavior of legacy lexers like
flex, lex, re2c.